Casing cutter



CASING CUTTER 2 Sheets-Sheet 1 Filed April 26, 1946 INVENTOR.

April 4; 1950 J.'E. DENNERLINE CASING CUTTER 2 Sheets-Sheet 2 Filed April 26, 1946 INVENTOR.

pulled from the well.

Patented Apr. 4, 1950 CASING CUTTER John E. Dennerline, Paola, Kans assignor of three-eighths to Brundrejd Oil Corporation, Oil City, Pa., a corporation t Pennsylvania.

, Application April 26, 1946, Serial No. 665,216

r l I My invention consists in certain new and useful improvements, in casing cutters employed to salvage casing stuckin a well such as an. oil or gas well.

In such practice the tool is lowered within the casing to the selected level and is then rotated fromabove to cause the cutter elements, carried by the tool, to sever the wall of the casing from within, and the severed portion of the casing is In general my improved cutter comprises three main tubular elements in assembled relation, a base which is sustained at the proper level within the casing as by means of a tailpipe or other support, a cutter body superimposed on the base and arranged for free rotation thereon, and a head in telescopic relation with the bore of the body, the exterior wall of the head having a downwardly tapering portion and the bore of the body having a complementary tapered portion. The connection' between the head and the body is such" that the body is caused to rotate with the head but has limited vertical motion relative thereto.

The cutter members carried by the head are spring-biased inwardly so that they are normally retracted, as while the tool is being inserted downwardly in the casing, or recovered from the casing after the severing operation has been made and the casing is to be pulled, but said members are forced radially outwardly as when the tool is bottomed in position in the casing and the head is caused to descend relative to the body and the complementary tapered portions thereof are moved toward nested relation. 7

In the accompanying drawings, wherein I illustrate the principles of my invention,

Fig. 1 is, an elevation of the tool with the. parts in cutting position. ,7

Fig. 2 is a vertical ection of the, same takenalong the line 22 in Fig. 1.

E Ii ig. 3 is a view showing the several elements and parts of the tool disassembled;

.Referring to the drawings, I indicates the base of the tool which is tubular, 2 ,the cutter body supported by the base and arranged for rotation thereon, and 3 is the head which is attached to they body in such manner as to rotate in unison therewith but capable of limited axial motion relative to the head, i

The base, the body and the head are tubular.

and of such exterior diameter a to be easily'inserted into and withdrawn from the-casing to be cut indicated at 4 in dotted lines. The lower bore of the base I is somewhat enlarged in diameter-and thread di ec iv the upp r d'o 5 claims, (o1. ice-#6.?)

the' v tail pipe 5 which supports the tool at the proper elevation for the cut. The upper bore of the head 3 is also enlarged and threaded for the attachment thereto of a pipe 6 which is of a length to reach the earth surface. This pipe is rotated to rotate the head 3 and the body 2 during the cutting operation.

The upper bore of the base and the lower bore of the body are of like diameter. The upper'borel of the body expands upwardly in diameter. The lower exterior diameter of the head is such that it has an easy fit in the upper bore of the base and the lower bore of the body, and is of suchv length that when the parts are in cutting relation it is telescoped with both the base and head. The intermediate portion 8 of the head is of up wardlyexpanding diameter and is arranged for nesting in the funnel shaped bore 1 of the body. At the upper end of the tapered portion 8 of the head 3 is an annular perimetral shoulder 9 arranged for engagement with the end of the body 2.

. The wall of the body is provided with a plu rality, preferably three, of equally spaced slots,-v

[0 extending axially of the bore and working in said slots are the head of screw studs II which are screwed into threaded holes in the wall of the head, thus attaching the body and head together in such manner that th body will rotate with the head but providing for a limited axial movement of the head relative to the body.

The wall of the body 2 is provided near the top of its bore portion I with a plurality of radial ports I2 in spaced relation with each other around the'body and interposed between the slots l0. Said ports are rectangular in cross section and. within each is slidably mounted a carrier block l3 having formed on its outer face a horizontal recess defined by the upper and lower flanges l4, and in each of said recesses is journaled a cutter wheel I5 rotating on a vertical pin the ends of which are seated in holes in said flanges. The

wheel is of such diameter that its perimetral cut-- ting edge extends outwardly beyond the edge of the flanges. The inner faces of the blocks iii are beveled to. correspond to the inclination of the' wall of the bore portion 1. M v

The exterior wall surface 01' the body 2 is provided with longitudinally extending grooves l6 th upper ends of which merge in the ports l2, l1 indicates leaf springs the lower ends of which are secured in the grooves l6 and their upper ends engage and press inwardly on the blocks [3, thus urging the blocks inwardly and normally holding the cutter wheels withdrawn within the;

' ports. 7

The wall of the tapered portion 8 of the head is provided with an annular series of spaced longitudinal grooves 18 in which the inner portions of the blocks I3 ride as the head moves inwardly in relation to the body, thus guiding the radial movements of the blocks.

The upper edge of the base I is provided with a concentric raceway l9 and the lower edge of the body 2 is provided with a like raceway 20 for antifriction device-s such as the balls 2|. Adjacent the raceway 19 the base I is provided with a perimetral groove 22 and a like groove 23 is formed in the lower portion of the body 2. 24 indicates a two-part collar having its upper and lower edges provided with inwardly extending flanges which fit in the grooves 22 and 23, and which is assembled and held in place by the .screws 25 extending through the collar sections and engaging threaded .holes in the base and body. Thus the base and body are attached together while the body may be freely rotated relative to the base.

In use the base is screwed into the end of the tail pipe 5 and the tool and tail pipe have been lowered into the well and bottomed at the right elevation, the rotation of the rotor pipe 6 will rotate the body 2 and the weight of the head 3 and the pipe 6 will cause the head to move downwardly relative to the body urging the carrier blocks outwardly and bringing the cutter wheels into cutting engagement with the wall of the casing 4 and causing the cutter wheels to sever the casing at the predetermined level. It is evident that the extent of the telescopic movement of the head 3 relative to the body 2 will determine the outward movement of the carrier blocks 13 and the cutter wheels 15 mounted in said blocks, and thus casing of difierent diameters may be cut with the tool without changes in the structure of the latter.

When the casing has been cut, an upward pull is exerted on the pipe '6 causing the head 3 to rise relative to the body 2, relieving the outward urgeon the carrier blocks and permitting the leaf springs-to retreatthe cutter wheelswithin the ports l2 where they contact with the casing wall. Continued upward motion of the pipe 6 will lift the tool and the tail pipe out of the well, and the severed portion of the casing may then be pulled out of the well.

In case a small pipe26, such as the two inch pipe, is'lnstalled in the Well and is not to be removed, the tail pipe 5, the tool and the rotor pipe 5 may be run down over the same and after the casing is severed the tool and its connections and the severed portion of the casing may be drawn up without disturbing the small pipe.

I claim:

1. In a casing cutter for insertion in the casing to be .cut, the combination of a tubular base arranged to be positioned withinthe casing at the selected elevation for the cut, a tubular body secured on the upper end of the base and rotatable relative thereto, the lower bore of the body matching the bore of the base and the upper bore of the body. expanding upwardly to form airusto-conical seat, a tubular head secured to the body to rotate therewith but having limited axial movement relative to the body, said head being provided with a frusto-conical perimetral surface which when the head and body are in juxtaposition nests in the frusto-conical seat in the body, cutter members slidably mounted in radial ports cut-through'the wall of the seat p.ortion of the body and spring-urged inwardly of the perimetral surface of the body, the frustoconical perimetral surface of the head, as the head moves into nested relation with the body, engaging said cutter members and forcing them outwardly into cutting contact with the wall of the casing, and a tail pipe attached to the lower end of the base of proper length to support the casing cutter at the proper elevation in the easing.

2. In a casing cutter for insertion in the easing to be cut, the combination of a tubular base arranged to be positioned within the casing at the selected elevationfor the cut, a tubular body secured on the upper end of the base and rotatable relative thereto, the lower bore of the 'body matching the bore of the base and the upper bore of the-body expanding upwardly to form a frusto-conical seat, a tubular head secured to the body to rotate therewith but having limited axial movement relative to the body, said head being provided with a frusto-conical perimetral surface which when the head and body are in juxtaposition'nests in the frustoconical seat in the body, and cutter members slidably mounted in radial ports cut through the wall of the seat portion of the body and springurged inwardly of the perimetral surface of the body, the frusto-conical perimetral surface of the head, as the head moves into nested relation with the body, engaging said cutter members and forcing them outwardly into cutting contact with the inner wall of the casing, the limited axial movement between the body and the head being provided by studs extending radially from thehead and slidably engaging longitudinal slots formed in the wall of the body.

3. In a casing cutter for insertion in the easing to be cut, the combination of a tubular base arrangedto be positioned. within the casing at the selected elevation for the cut, a tubular body secured on the upper end of the base and rotatable relative thereto, the lower bore of the body matching the bore of the base and the upper bore of the body expanding upwardly to form a frusto-conical seat, a tubular head secured to the body to rotate therewith but having limited axial movement relative to the body, said head being provided with afrusto-conical perimetral surface which when the head and body are in juxtaposition nests in the frusto-conical seat in the body, and cutter members slidably mounted in radial ports cut through the wall of the seat portion of the body and spring-urged inwardly of the perimetral surface of the body, the frustoconical perimetral surface of the head, as the head moves into'nested relation with the body, engaging said cutter members and forcing them outwardly into cutting contact with the inner wall of the casing, the axial bores of the base, the body and the head forming a continuous opening to permit the casing cutter to be slid down over a small pipe extending down the well.

4. In a casing cutter-for insertion in the easing to be cut, the combination of a tubular base arranged to be positioned within the casing at the selected elevation for the cut, a tubular body secured on the upper end of the base and rotatable relative thereto, the lower bore of the body matching the bore of the base and the upper bore of the body expanding upwardly to form a frustoconical seat, a tubular head secured to the body to rotate therewith but having limited axial movement relative to the body, said head being provided with a'frusto-conical perimetral surtaposition nests in the frusto-conical seat in the body, a series of ports cut in the wall of the body and arranged circumferentially thereof, carrier blocks mounted in said ports to slide therein radially of the body, said blocks being spring-urged inwardly of the body, cutting wheels journaled on vertical axes in said blocks and having their perimetral edges extending outwardly therefrom, the frusto-conical perimetral surface of the head, as the head moves into nested relation with the body, engaging the blocks and forcing them outwardly to bring the cutting wheels into cutting engagement with the wall of the casing.

5. The subject matter of claim 4 characterized by the provision of longitudinal grooves in the 1 6 wall of the tapered portion of the head engaged by the inner portions of said blocks for guiding the movement of the latter as the head moves inwardly in relation to the body.

JOHN E. DENNERLINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,947,726 McCullough Feb. 20, 1934 2,188,409 Lane Jan. 30, 1940 2,208,011 Anderson July 16, 1940 

